The weed- and garbage-choked thicket that dozens of officers waded through Monday in the Gilgo Beach area made the search for Shannan Gilbert a difficult task, officials said.

Officers had hoped to take advantage of the fact that the snow is gone and the vegetation has not yet grown for spring, giving perhaps the least obstructed view yet.

But the area of the search, up to 71/2 miles long, and the terrain, dense with bramble and trash, has frustrated even the department's cadaver dogs.

"They don't like getting smacked in the face with the bramble," Suffolk Chief of Detectives Dominick Varrone said of the three cadaver dogs and one tracking dog on the site Monday. "We learned from that that we can't rely entirely on the dogs."

Officers first began to search the area in December to look for Shannan Gilbert, 24, of Jersey City, N.J. They found four bodies that month, none of them Gilbert. But that search was hampered by cold weather.

During Monday's search, two officers stood aloft in the buckets of ladder trucks, peering down over the area, one eyeballing it and the other videotaping it. The buckets can be raised 100 feet into the air.

The trucks, supplied by the North Babylon, Babylon and Islip fire departments, offered a panoramic perspective since the view from ground level is obstructed.

"In my years here, this is the first time I've known the trucks to be used in this way," said Joseph Williams, commissioner of the Suffolk County Fire Rescue and Emergency Services.

With such limited visibility on foot, a searcher who is already having trouble finding a clear spot to place his boot would have to all but stumble on a body in order to discover it.

"The terrain is very rough," Police Commissioner Richard Dormer said before three bodies were found Monday. "It's not easy to traverse. It's a tough area. It's very easy to miss something."

Beer bottles and balloons, shredded tires and all manner of garbage lay strewn about the field where officers and dogs went about their work.

What's more, police have come in contact with poison ivy, making an already tough job harder. Twenty officers have already been treated for the ailment.

"It's going to be slow, comprehensive and methodical," a police spokeswoman said.